The present invention relates to an electronic thermometer and, more particularly, to an abnormal condition detecting system in an electronic thermometer.
Recently, an electronic, clinical thermometer has been developed, which employs the temperature measuring system of the highest value holding type. The highest value holding system determines the completion of the temperature measuring operation when the highest value does not change for a period longer than a preselected period of time.
A typical construction of the electronic thermometer is disclosed in U.S. Pat. No. 4,377,171, entitled "ELECTRONIC THERMOMETER", issued on Mar. 22, 1983. In such an electronic thermometer, an accurate measurement is not ensured when a sensor probe is erroneously separated from a desired portion of a body of a person to be measured before the measurement completion signal is developed.
Accordingly, an object of the present invention is to provide an electronic, clinical thermometer which ensures an accurate measurement operation.
Another object of the present invention is to provide an abnormal condition detection system in an electronic thermometer for visually or audibly alarming an abnormal condition of the electronic thermometer.
Other objects and further scope of applicability of the present invention will become apparent from the detailed description given hereinafter. It should be understood, however, that the detailed description and specific examples, while indicating preferred embodiments of the invention, are given by way of illustration only, since various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art from this detailed description.
To achieve the above objects, pursuant to an embodiment of the present invention, the measured highest value is stored in a first memory means. The temperature value now measured is introduced into a second memory means. A fixed value, for example, 1.5.degree. C. is added to the now measured value, and the addition result is compared with the highest value stored in the first memory means. If the addition result is smaller than the highest value stored in the first memory means, a determination system determines that the electronic thermometer is in an abnormal condition.
In another preferred form, the temperature value now measured and introduced into the second memory means is compared with a fixed value, for example, 35.degree. C. If the now measured value is smaller than the fixed value, a determination system develops a control signal to announce an abnormal condition of the electronic thermometer.
In still another preferred form, a fixed ratio, for example, 0.99 is multiplied by the highest value stored in the first memory means. The product is compared with the now measured value. If the now measured value is smaller than the product, a determination system determines that the electronic thermometer is in an abnormal condition.